It is often desirable to formulate a detergent composition that includes a bleaching agent. Many bleaching agents that provide bleaching and/or oxidizing properties are not compatible with many of the components found in a detergent composition. Because of this lack of compatibility, the detergent composition may lose bleaching activity and/or cleaning activity over time. For example, many bleaching agents have a tendency to react with components in a detergent composition including surfactants, alkaline components, and water. As a result, detergent compositions that include bleaching agents have a tendency to lose bleaching activity and cleaning activity over time unless steps are taken to physically separate the bleaching agent from the other components of the detergent composition.
Many techniques are available for coating and/or encapsulating bleaching agents so that the bleaching agents can be used in detergent compositions to provide use compositions having desired levels of bleaching and cleaning. Several techniques utilize a fluidized bed to encapsulate the bleaching agent. For example, see U.S. Pat. No. 4,657,784 to Olson, U.S. Pat. No. 4,830,773 to Olson, U.S. Pat. No. 4,731,195 to Olson, U.S. Pat. No. 4,681,914 to Olson et al., and International Publication No. WO 2004/053040 A2. Additional techniques that utilize a fluidized bed can be found in, for example, U.S. Pat. No. 3,650,961 to Hudson, U.S. Pat. No. 3,908,044 to Alterman, U.S. Pat. No. 3,908,045 to Alterman, U.S. Pat. No. 5,200,236 to Lange et al., and U.S. Pat. No. 5,230,822 to Kamel et al.